pub fn dp_rec_mc(amount: u32) -> u32 {
    [0, 1, 1, 2, 2][amount as usize % 5] + [0, 1, 1, 2, 1, 2, 1, 2, 2, 3][amount as usize / 5 % 10] + (amount + 50) / 100
}
